1. Technical Field
The present invention relates to an electronic device that receives a satellite signal from a positioning satellite to perform positioning, and a reception control method thereof.
2. Related Art
A technique that increases an opportunity to obtain positioning information about an ephemeris or the like included in a satellite signal transmitted from a global navigation satellite system (GNSS) satellite to reduce time to first fix (TTFF, time from when power of a satellite signal receiver is turned on to when position information is output) is known. Since the positioning information has an effective life, in order to perform accurate positioning in a positioning device, it is necessary to maintain positioning information of which the effective life is not expired. In a device disclosed in JP-A-2009-270929 mentioned below, a satellite signal is received from a GNSS satellite for a predetermined time before an effective life of maintained positioning information is expired to obtain positioning information again.
However, in the technique disclosed in JP-A-2009-270929, when the device is disposed at a place that a satellite signal does not reach, for example, in a room and is left as it is, the reception of the satellite signal fails, and thereafter, the obtainment is attempted again every predetermined time to repeat the failure. Further, when the device is left at a place that the satellite signal reaches, the reception of the satellite signal succeeds every predetermined time to obtain the positioning information. However, the latest positioning information is effective, but the previously obtained information is not effective for use.
In this way, when the device is left, the reception process is performed to repeat the failure every predetermined time, or to obtain the positioning information that is not used.
When the device is operated by driving power of a portable battery, power consumption of the reception process is wasteful, and thus, there is a problem in that a user cannot use the device for a sufficient time due to lack of the battery residual when the user desires to use the device for positioning.